Reclosing system for circuit breakers, including variable stroke disconnect switch means



April 20, 1954 E. JANSSON ET AL RECLOSING SYSTEM FOR 01 VARIABLE STROKEDISCONNECT SWITCH MEANS Filed Sept. 8 1951 4 Sheets-Sheet l 2,676,285RCUIT BREAKERS. INCLUDING April 20, 1954 G. E. JANSSON ET AL 2,676,285

RECLOSING SYSTEM FOR CIRCUIT BREAKERS, INCLUDING VARIABLE STROKEDISCONNECT SWITCH MEANS Filed Sept. 8, 1951 4 Sheets-Sheet 2 Aprll 20,1954 G. E. JANSSON ET AL 2,676,285

RECLOSING SYSTEM FOR CIRCUIT BREAKERS, INCLUDING VARIABLE STROKEDISCONNECT SWITCH MEANS Filed Sept. 8, 1951 4 Sheets-Sheet 5 Aprll 1954G. E. JANSSON ET AL 2,676,235

RECLOSING SYSTEM FOR CIRCUIT BREAKERS, INCLUDING VARIABLE STROKEDISCONNECT SWITCH MEANS Filed Sept. 8 1951 4 Sheets-Sheet 4 PatentedApr. 20, 1954 RECLOSING SYSTEM FOR CIRCUIT BREAK- ERS, INCLUDINGVARIABLE STROKE DIS- CONNECT SWITCH MEANS Gustav E. Jansson, Salzer,Brookline,

North Quincy, and Erwin Mass., assignors to Allis- ChalmersManufacturing Company, Milwaukee, Wis.

Application September 8, 1951, Serial No. 245,724

Claims. 1

This invention relates to automatic reclosing systems for electriccircuit interrupters and. more particularly to means for controllingfluid blast circuit breakers having serially connected arcing anddisconnect contacts for automatic high speed reclosing duty.

Heretofore, circuit breakers have been provided which remove a faultfrom a line and reclose within about ten to twenty cycles of a sixtycycle current wave. If the fault was not removed upon initial opening,th breaker would open a second time and would then remain permanently inthe open position.

In fluid blast circuit breakers of standard design the weight and thestroke of the arcing or interrupting contacts are relatively small and.the weight and stroke of the disconnect contacts are relatively large.Consequently, the speed of operation of the interrupting contacts isrelatively rapid and that of the disconnect contacts relatively slow.Therefore, it is possible to fully separate the interrupting contacts inthe order of 2.5 to 3.5 cycles of the current wave, while it takes aboutfifteen cycles of the current wave to achieve full separation of thedisconnect contacts. In the case of rapid reclosing the reclosing timemust be in the order of ten to twenty cycles, thus the movabledisconnect contact of a fluid blast circuit breaker of conventionaldesign is incapable of achieving the required speed of operation.

Rapid reclosing of a circuit breaker may be achieved by interlocking thearcing or interrupting contacts and the disconnect contacts so as topreclude opening of the latter upon initial opening of the former, butpermitting opening of the latter upon repeated opening of the former.

A circuit breaker which is provided with such an interlock recloses thecircuit upon initial opening thereof by means of the arcing orinterrupting contacts rather than the disconnect contacts. Reclosing ofthe circuit by means of the interrupting contacts is a serious drawbacksince it imposes an additional heavy duty upon the interruptingcontacts, for which they are generally not suited.

Therefore, in the invention claimed new and improved controlling meansare provided for a circuit interrupting device which employs a pluralityof cooperating arcing contacts in series with a plurality of cooperatingdisconnect contacts. Upon initial opening of the power circuit thearcing contacts separate followed by the separation of the disconnectcontacts a predetermined distance. The are is extinguished by a blast offluid under pressure and upon are extinction the arcing contactsreengage followed by the reengagement of the disconnect contacts. If thecircuit difl'iculty still exists the arcing contacts again separatefollowed by the separation of the disconnect contacts a secondpredetermined distance. The disconnect contacts separate the second timea greater distance than the first time to provide upon permanentinterruption a sufiicient amount of circuit insulation to keep the arefrom restriking across the gap in the power circuit.

It is, therefore, one object of the present invention to provide a newand improved control system for a fluid blast circuit breaker havingserially connected arcing and disconnect contact means to provide highspeed reclosing service in which the electric circuit is interrupted byone pair of contacts and closed by another pair of contacts.

Another object of this invention is to provide a new and improvedcontrol system for high speed reclosing duty of a circuit interruptingdevice in which one pair of contacts interpose upon initial interruptiona certain amount of circuit insulation and upon repeated interruption alarger amount of circuit insulation.

A further object of this invention is to provide a new and improvedcontrol system for a circuit breaker in which the electric circuit isinterrupted by one pair of contacts in a medium of substantially higherdielectric strength than air at atmospheric pressure and is closed by 'asecond pair of contacts arranged at atmospheric pressure.

A still further object of this invention is to provide a new andimproved circuit breaker structure in which contact means are seriallyconnected into a circuit with a pair of cooperat ing arcing contacts andare adapted to insert selectively into the electric circuit a relativelysmall amount of circuit insulation at a gap of relatively small lengthin a medium of relatively high dielectric strength and a relativelylarge amount of circuit insulation at a gap of increased length formedat least in part of air at atmos pheric pressure.

Objects and advantages other than those set forth will be apparent fromthe following description when read in connection with the accompanyingdrawings, in which:

Fig. 1 is a diagrammatic view partly in elevation of a circuit breakerand operating system therefor embodying the present invention, thecircuit breaker being open;

Fig. 2 is an enlarged view of the blast valve and arcing contactoperating mechanism of Fig. 1 showing the contacts closed;

Fig. 3 is a View in cross section taken along the line IIIIII of Fig. 2looking in the direction of the arrows;

Fig. 4 is a view of the latching mechanism shown in Fig. 1 but showingthe mechanism in the disconnect contact closed position;

Fig. 5 is a diagrammatic view partly in elevation of a circuit breakerand operating system therefore employing another embodiment of theinvention, the circuit breaker being open; and

Figs. 6 to 8, inclusive, show in front elevation three differentpositions of the linkage by which the disconnect contact of the circuitbreaker illustrated in Fig. 5 is operated and restrained in closedposition.

Referring to Fig. l of the drawing, the circuit breaker operating systemcomprises a supporting frame structure (not shown) topped by a platformit. A storage tank lit for air under pressure is arranged below platforml2. Platform 1% supports four insulating columns one of which, column il, houses a disconnect switch comprising a stationary tulip contact it?and a cooperating movable bayonet contact it. An insulating column l1houses a current transformer another insulating column i8 is adapted tobe rotated by a fluid motor it to cause opening and closing of a pair ofcooperating arcing contacts and 2 l. The contacts 29, 2 i, which areshown open in Fig. l, are housed in a fourth insulating column which isgenerally designated Column 22 comprises a lower insulator in. which aninsulating blast tube as is arranged. A1netallic blast tube connectstank 3 with insulating blast tube 24. A casting Z6 is supported on oneend thereof by the hollow insulators 23 and 2E. Attached to the otherend of casting 25 is a disconnect and reclosing switch structuregenerally designated 3t. The disconnect and reclosing switch structureis supported on the left side thereof by column li. Casting 25 houses adifferential type blast valve 3i under control of an auxiliary valve andan operating linkage 33 for contact 2i. Casting Zii supports in turn thehollow insulator (i i in which the tubular contact 2% is arranged.Insulator 3 2 is topped by a hood 35 defining two venting passages 3%for the exhaust of are products. Stacks of parallel spaced plates 3?serve to cool the are products before they are released to atmosphere.An electric line terminal it forms an integral part of hood Insulatingcolumn is is likewise topped by a hood 35! of which electric lineterminal ill forms an integral part. Column M consists of two tubularinsulators 33 and ie between which a casting G5 is arranged. Castingdefines an internal cylindrical surface id for a piston 47 supportingcontact i6. Piston ill is adapted to be operated by an insulating rodwhich, in turn, is adapted to be operated by a metal rod 19.

Casting 45 of column M is conductively connected to the currenttransformer til within column H by a bridging member 5?. r'l. member 53connects the current transformer within column ll withthe disconnect andreclosing switch 3ll.

The current path through the entire breaker structure is as follows:terminal hood 35, stationary contact 26, movable contact 2|, casting 26,disconnect and reclosing switch 39, member 5a. current transformer 55within column l1, bridging member 5!, casting d5, bayonet Conta t 16,tulip contact 55, hood 39, terminal cc.

Referring more particularly to Figs. 2 and 3 in which the arcing contactmechanism is shown in contact closing position, casting it forms ahousing for a blast valve generally designated 3|. Blast valve 3|comprises movable valve element 55 which is acted upon by helicalbiasing spring 56 tending to press valve element b5 against valve seat57. Normally, air under pressure act upon both the right and left endsurfaces of valve element 5%. In the closed position of valve iii theeffective area of the right fluid pressure reactive surface of valveelement is larger than the effective area of the left pressure reactivesurface thereof The air pressure tending to move valve element 55 fromits normal position shown in Fig. l to the rightis much less than thesum of the air pressure and the pressure of spring ts both tending topress valve element 553 to the left against valve seat 51. The spacesituated at the right side of valve element adapted to be vented bymeans of pipe 58, auxiliary valve chamber 55 and an orifice iificontrolled by valve element 6 i.

Valve element iii is adapted to be operated by means of stem 62 restingin slide bearings 63. Stem 62, in turn, is adapted to be operated by acrank mechanism which has generally been indicated at iii. Crankmechanism it is associated with an operating shaft 6t adapted to beoperated by insulating column iii. The right end of stem 82 issurrounded by a helical biasing spring of which one end rests on acollar 86 on stem 62, while the opposite end rests against valve housing55 Upon rotation of shaft 54 in the clockwise di rection (as seen inFig. 3) stem 62 moves to the right against the action of biasing springE5 and moves valve element 6! from the left valve seat 68 to the rightvalve seat 63 of valve housing 58. Consequently, pipe 12 interconnectinga blast passage 73 with valve housing ts is blocked and valve housing 59vented, to atmosphere. This causes the pressure on valve elementdirected from left to right to exceed that directed from right to left,resulting in rapid opening of blast valve 3i. The blast of air underpressure which is admitted from blast passage 3 to the gap formedbetween separated contacts 28, El tends to extinguish the arc which isinitiated upon parting of movable contact 2i from stationary contact 20.

Separation of contacts and 2| is effected by an arm T4 of crankmechanism '50. Arm 2'4 extends into a U-shaped abutment member i5forming an integral part of rod l is for actuating a contact operatingtoggle mechanism generally designated 33. That toggle mechanismcomprises link HS adapted to operate links '57 and i8, of which theformer is adapted to operate two links it and 8%). Links ii and it arejoined together at SI and link it is fulcrumed at B2, in casting 26.Links 11 and T9 are joined together at 83, and link 19 is fulcrumed at84, in casting 26. Links is and 89 are joined together at B5, and linkBil is pivotallyv connected at to movable contact 2!. Arm 74 andU-shaped abutment member 15 form a lost motion connection between shaft64 and link 16 which is responsible for a small time delay betweenopening of blast valve 3! and separation of contacts 2c and 2!.

When crank mechanism in is rotated in the clockwise direction (as seenin Fig. 3), arm 14 moves a predetermined distance before acting upon rodH4; then it engages the left abutment surface of member 15 moving rod H4from right to left. Rod'I I4 acts upon a piston 89'which,

in turn, acts upon spring 90 in spring housing 9|. Spring 90 providesthe necessary contact pressure in the closed position of the breaker andis compressed by the action of arm I4 during the circuit interruptingoperation. When link I is actuated by rod I I4 to the left, toggle TI,I8 collapses. This causes rotation of link 19 about pivot 84 in theclockwise direction resulting in downward movement of the movablecontact 2|.

Movable contact 2I comprises a radially inner portion 92 and a radiallyouter portion 93. The outer portion 93 is telescopically arranged in acylindrical guiding member 94. The inner por tion 92 is, in turn,telescopically arranged in the outer portion 93. Spring 95 which isarranged between portions 92 and 93 biases the former upward. As clearlyshown in Fig. 2, there is a certain axial play or lost motion betweenportions 92 and 93 and these two portions are provided with cooperatingabutments 96 and 91, respectively, which limit relative movement ofportions 92 and 83 when the latter is disengaged from tubular stationarycontact 20.

Guiding member 94 is provided with spring biased contact segments 98 forreducing the contast resistance between that member and outer portion93. In a similar way, outer portion 93 is provided with contact segments99 for reducing the contact resistance between that portion and theinner portion 92. The inner portion 92 serves as arcing contact orinterrupting contact while the outer portion 93 serves as currentcarrying contact. When the outer portion is ac tuated downward by togglemechanism 33, the outer portion 93 separates first from stationarynozzle contact 20. Upon a predetermined downward travel of portion 93abutment 91 thereof engages the flange or abutment 90 of portion 92,thus compelling the latter to separate from nozzle contact 20.

In order to cause reclosing of the blast valve 3i at the end of thecircuit interrupting operation, an intermediate link I00 is arrangedbetween arm '1 and connecting rod 8? of crank mechanism I0,

rod 8! is provided with an abutment member 88 adapted to be engaged by astationary abutment 08a. Abutments 8B and 88a cause buckling of thetoggle formed by members 87, 00 at the end of the circuit openingoperation. This in turn permits spring 65 to move stem 62 to the left,thus moving valve element 0! from right valve seat 69 to left valve seat58. Consequently, compressed air is being admitted to blast valve 3!through passage I2 and 58, resulting in closing of blast valve 3|, thusprecluding continued consumption of compressed air upon interruption ofthe circuit and interposition of a suificient amount of circuitinsulation by the dis connect and reclosing switch 30.

The disconnect and reclosing switch generally indicated at 39 comprisesa stationary tulip type contact I0 I made up of a plurality of springbiased contact fingers and a cooperating movable rod contact I02.

The pair of contacts I M and I02 is arranged in a chamber I03 defined byan insulator I04. The left end of insulator I0; is supported by member52! resting on the current transformer column I! while its right end issupported by a cylinder 5&5 of a pneumatic motor comprising a pistonI05. The piston I00 arranged in cylinder I05 operates contact I02 and isbiased to contact closed position by a helicalspring I01. Admission ofair un- ,der pressure from casting 20 to cylinder I 05 may biasedauxiliary latch hi2.

occur through duct I08, a. check valve I20, port I09 and ports H0 andI23 in the left head of cylinder I05.

The flow of compressed air through duct I00 and ports I09, H0 iscontrolled by auxiliary piston valve I II operated by a lever Il2. LeverI I2 cooperates with an abutment II3 secured to the operating rod H4 ofthe operating linkage 33 of interrupting contact 2|. Piston valve III isprovided with a venting port I I5 and a spring I It normally biasingvalve III to the left, to open or venting position. Valve III begins toclose upon engagement of lever II2 by abutment H3 and rotation of theformer in the clockwise direction, as seen in Fig. 1. Cylinder I05 isprovided with two lateral openings I I1 and H8 of which one is arrangedrelatively close to contact IM and the other relatively remote fromcontact IOI.

0n occurrence of a fault motor I9 rotates column I0, resulting inseparating interrupting contact 2I from interrupting contact 20, openingof the blast valve 3| to produce an arc extinguishing blast across thegap formed between the separated contacts 20, 2| and closing of theauxiliary valve comprising a piston II I. Upon opening of blast valve 3Icasting 20 is filled with air under pressure. Air under pressure isallowed to flow from casting 26 through duct I00 and ports I05, I50 intochamber I03, thus filling chamber I03 with a medium having a relativelyhigh dielectric strength. Closing of valve I II by abutment H3 and leverI I2 occurs substantially simultaneously with the separation of theinterrupting contacts 20, 2 I. Pressure rapidly built up in chamber I03and cylinder I05 results in separation of contacts Idi and I02 by springpneumatic motor I05, I05.

The operating and control arrangement for contacts I5 and I B is asfollows:

The operating mechanism for contact I0 comprises a spring biasedpneumatic motor generally designated I25. Motor I25 and the motorcomprising cylinder I05, piston I 06 and spring I01 constitute anoperator for the disconnect contact means IOI, I02 and I5, I0. Motor I25effects separation of contacts I 5, IB by spring means I20, andreclosing of contacts I5, I6 by pneumatic action. The helical spring I20is arranged between a piston I21 and a cylinder I28 of motor I25. Apiston type dump valve I29 which opens to atmosphere is provided to dumpmotor 525 when piston I21 approaches the top end of its stroke and alsowhile it is impelled downward by the action of spring I26.

The operating linkage for contact It comprises two levers I30 and I3l.The former is pivoted at I32 and the latter at I33. A tie link 134interconnects levers I30 and I3l. An operating rod I35 and a link I44interconnect piston I 21 of motor I25 and lever I3I. Lever I3I carries apin I36 which is provided with a roller I31 adapted to be engaged by camsurface I38 of a latch I39. Latch I39 is biased by a spring I40. LatchIE9 is pivoted at I4! and controlled by a spring Auxiliary latch M2 isin turn controlled by tripping solenoid I43.

The pneumatic control system of the breaker includes pipeline I00leading from the tank I3 to magnet valves I4? and I 40. Both thesevalves are of the solenoid type; the former is a tripping valveenergized when the breaker is to open; the latter is a closing valveenergized when the breaker is to close. Pipeline I49 leads from trippingvalve !41 to one end of pneumatic motor I9 and to one end of a pistonvalve I53. A pipeline I5! leads from closing valve I08 to the otheramazes end of pneumatic motor I9 and to the other end of piston valveI58. Pipeline Ito connects one ta of the fluid motor piston valve unitit, lbs with fluid motor I25. This pipeline is under the control ofspring biased solenoid operated valve I52. The dump valve I25) of fluidmotor M is operated by a lost motion mechanism and a rod I53 attached tolever I3I.

The control circuit for the disconnect contact includes an auxiliaryswitch it l adapted to be directly operated by the piston Hit of fluidmotor I9.

The manual reclosing cutout switch comprising a pair of switch armsinsulated from each other is placed in the lower positon shown to pro--pare the energizing circuit of tripping solenoid I43 when an automaticreclosing cycle is not desired.

Relay I5! is a conventional fault responsive time delay relay forinitiating the operation or" the breaker at the occurrence of a faultalong the line for the protection of which the breaker is provided.Relay IE8 is a conventional reolosing relay and is used for energizingclosing solenoid valve I48 upon an initial separation of interruptingcontacts 2i} and ill and for energizing tripping solenoid I43 uponrepeated separation of interrupting contacts 2' 3 and 25. Pushbut'ton'li ifii enables manual tripping and pushbutton switch I62 manualclosing of the breaker; both reopen with a time delay.

The system being in the condition shown. in Fig. l, the open circuitbreaker is closed by closing switch I62. This results in sect. closingof interrupting contacts 2i and disconnect contacts I5, It. Moreparticularly, the operation of switch 52 causes energisation of solenoidvalve I43 from a battery bit through switches I62 and I54. Valve Hitadmits com pressed air through pipe IEiI to the left ends of motor I?)and of valve I50. Valve 1% moves to the right, thereby closing the leftdumping p it of motor I9, opening the right dumping port of motor It,and opening pipe 159. Piston also moves to the right to cause column itto rotate counterclockwise (as seen in Fig. 2-) to close contacts Ell,2%. Upon movement to the left by spring H 3, valve II! opens to ventcylinder liit and contacts lei, I82 reclose if they were still open.Link Itii and connecting rod iii are rose in the position shown whileblast valve ti remains closed. Switch id iopens the energized circuit ofvalve I43, and the valve recloses.

When piston ifill reaches a predetermined position air may pass from thecylinder of motor is through pipe I59 and valve I52 to motor 125,causing upward movement of piston i2'l against the bias of spring I26and closing of contacts IE, it. When piston i2l approaches the top endof its stroke, rod l53 moves valve its to dump the air contained incylinder IZii. The actuating means of contact I6 completes its stroke bymementum, roller I31 rolling on cam surface H33 during such movement.When contacts 55, it are closed, roller 536 reaches the notch in surfaceItt. Spring Mil causes latch use to pivot to cause engagement of theroller with the notch. Latch I42 is pulled into latching position tomaintain latch 39 in the position reached there by, in which itmaintains contacts it, iii closed. The above referred to sequence ofclosing of contacts 2i], 2i and I5, I55 isdue to the interlocking ofmotors I 9 and 125 through pipe its and to the time required to build upsufficient pressure 12 low piston I21 to move it against the bias ofspring I26.

Manual opening of the circuit breaker is eifected by actuating openingswitch IEI, causing energization of trip solenoid valve it! from batteryit through switches ltI and 54. Valve Ml admits air, through pipe use,to the right ends of motor I9 and of valve I50. Valve I59 moves to theleft, thereby opening the left dumping port of motor I9, closing theright dumping port of motor is and closing pipe 159.

Piston 555 also moves to the left to cause column It to rotate clockwise(as seen in Fig. 3). Blast valve BI is thereby opened and contacts 20,25 are separated to open the circuit. After the last between contacts2t, 2| has had time to extinguish the arc, valve IIi admits air tocylinder its to cause opening of contacts till, I02. Switch I5 3 opensthe energizing circuit of valve ml, and the valve recloses.

Switch [5 t also completes a circuit from battery M53 through switch itI, switch Itt, solenoid i and switch I54, back to the battery. Sole-.oid M3 withdraws latch M2. The latter releases latch 539. Under theaction of gravity and of spring 25, the disconnect contact actutingmeans moves latch 39 back to the un i lied position shown, roller i3?rolling on cam E355 while disconnect contact iii returns 0 the openposition shown.

Wl'ien piston r55 approaches the end of its e formed by link tilt andconnecting rod 81 to reclose blast valve 3i. In order to preclude areclosing operation when his desired to manually a permanentinterruption of the circuit, switches its and 162 may be provided withan interlock iii so that switch H32 cannot be operated as long as switch256 is in the upper or reclosing position.

The circuit breaker being closed, relay I51 is energized upon occurrenceof a fault condition. If switch i56 is in the lower position shown,relay merely causes tripping of circuit breaker if switch It! had beenclosed as above de scribed.

If switch W8 is placed in the upper (reclosing) position, relay i5?likewise connects the solenoid of valve Ml to the battery. in addition,the motor of reclosing relay IE3 is connected to the batterry throughrela I5! and switch I55. Reclosing relay i558 starts and closes acircuit maintaining its motor energized while its drum completes a fullrevolution. Energization of the circuit of solenoid valve Nil causesadmission of compressed air to the right side oi fluid motor 59 andpiston valve I59. Consequently, piston or" motor Iii and the movablevalve element of valve I59 are moved from right to This movement ofpiston I55 causes a rotation of column it which in turn causes openingof blast valve 3i and separation of contacts and 2|. Upon separation ofcontacts 252 and 2 contacts and Hi2 are separated by the action of fluidmotor 185, I05, as previously described. Toggle 3i, collapses and'recloses blast valve 3|. However, check valve I20 retains the air incylinder Hit and thus prevents premature reclosure of contact 382. RelayI5? returns to the position shown.

The movement of piston Iii: to the crates the auxiliary switch 15:3,gizes solenoid valve i4! and closes the circuit of solenoid valve #48through switch 553. Consequently the flow of compressed air through pipeleft als opic I49 is interrupted and a flow of compressed air isestablished through pipe II. The latter flow causes a motion of thepiston I55 of motor I 9 and of the movable element of valve I59 fromleft to right. This movement of piston I55 results in a rotation ofinsulating column I8 whereby interrupting contacts 26 and 2I arereclosed. The auxiliary valve I II for controlling the operation ofcontacts IIIII, I02 is opened by the biasing spring IIS substantiallysimultaneously with reclosure of interrupting contacts 20, 2I asabutment H3 is moved to the right by column I3. This results in ventingof fluid motor I 65, I55 through vent opening I I5 and closing ofcontacts I05, I82 after contacts 21), 2I have reclosed.

The movement of the valve element of piston valve I55 to the rightcauses admission of air under pressure from the cylinder of fluid motoris to pipe I59. Pipe I59, however, is sealed by solenoid valve I52since, as piston I55 moves from left to right, auxiliary switch I54energizes solenoid valve I52 from battery I63 through relay I58.Solenoid valve I52 closes against the action of its biasing spring.Switch I54 also deenergizes solenoid valve I48, which returns to theclosed position shown.

What happens further depends on whether or not the fault still prevailsat the time when contacts WI and I82 reengage. Relay I58 returns to theposition shown but if the fault does not prevail during that time,nothing else happens, i. e., service continuity is maintained. If thefault still persists at the time when contacts IIII and I82 reengage,the operating cycle of the breaker continues and a permanentinterruption of the circuit is effected by the breaker.

Permanent interruption is initiated by reenergization of relay I51,resulting in reopening of solenoid valve M? and readmission ofcompressed air to motor I9. Piston I55 of motor I9 then moves from rightto left,-which results in momentary opening of blast valve 3i andseparation of interrupting contacts 28 and 2I, and, therefore,reinterruption of the faulted circuit. Relay I57 again returns to theposition shown. Thereafter contacts iIlI and H52 part under the actionof fluid motor I95, I06. At that time the reclosing relay ISt energizesthe tripping relay M3 through switch I, whereby latch I42 is moved incounterclockwise direction, thus releasing main latch I 39. Roller I37is deprived of its support and spring I255 is free to move linkage I30,I34, I3I from its upper position, shown in Fig. 4, to its lowerposition, shown in Fig. 1. This completes the opening operation of thecircuit breaker and results in the formation of a gap of required lengthbetween contacts I5 and I6.

Upon permanent interruption contacts 25, 2! and IE, IS remain separated.Contacts IIlI and IIIZ reclose when contacts I5, I6 are separated a safedistance from each other. The time at which contacts IHI and I02 recloseis determined by the size of a bleed hole I 2I by which chamber IE3 isvented. To be able to vary that time, bleed hole I2! may be providedwith an adjustable needle valve I22.

It will be obvious from the foregoing that this embodiment of theinvention shown comprises three principal pairs of contacts, 1. e., apair of arcing or circuit interrupting contacts 20, 2|, a separate pairof circuit closing contacts IUI, I22 and a separate pair of disconnectcontacts I5, I

It will also be apparent from the foregoing that each pair of contactshas a. separate operator.

The pair of arcing or interrupting contacts 20, 2| is separated andclosed by the fluid operator I9, the pair of closing contacts IIII, I02is separated and closed by the combined fluid and spring motor 38 andthe disconnect contacts I5, I6 are separated and closed by the combinedfluid and spring motor I25.

Fluid motor IS! and combined fluid and spring motor I25 are arranged atground potential, whereas combined fluid and spring motor 30 is arrangedat the same elevated potential as housing 25 and all the metallic partsthat are associated with it, including the blast valve 3i.

Fig. 5 illustrates another embodiment of the invention as appiied to anair blast circuit breaker structure of the same type as illustrated inFig. 1. The circuit breaker structures of Figs. 1 and 5 are identicalexcept that the disconnect and reclosing switch 39 and its operatingmechanism have been omitted from the embodiment of Fig. 5 and theoperating means for the disconnect switch 45, It has been modified sothat the disconnect contacts I5, Iii may be opened to provide aplurality of air gaps of varying size. Structural elements of Fig. 5which are identical with those of Fig. 1 have the same referencecharacters.

On the occurrence of a fault on the power circuit controlled, motor itrotates column I8, resulting in the separation of arcing contacts 26]and iii and the opening of the blast valve 3i to produce an arcextinguishing blast across the gap formed between the separated contacts20, 2i. Disconnect contacts I5 and I6 separate instantly after theextinction of the are formed between arcing contacts ZII, 2i. Contacts25, 2I are caused to reengage by the action of motor I9 and rotatingcolumn It. The lowest position of contact I5 during the initial arcextinguishing operation is illustrated in Fig. 5 by dotted lines. If thefault condition still prevails at the time contacts I5 and It reengage,the circuit breaker is tripped again, resulting in sequential separationof contacts 20, 2! and I5, I6. This time, however, disconnect contactIE3 is actuated to the position shown in full lines in Fig. 5.

The operating and control means for achieving this particular type ofoperation is as follows:

The operator or operating mechanism for contact I5 comprises two springbiased pneumatic motors I'it and I25. Motor 570 effects the shortopening stroke of contact I6 and recloses contacts I5 and I6. Motor I25effects the long opening stroke of contact I6 and recloses contacts I5and Iii after contact I5 has reached its lowermost position shown inFig. 5. Motor Ilil effects separation of contacts I5, It by spring meansI?! and eifects reclosing of contacts I5, It; by pneumatic action.Spring means III are arranged between piston H2 and cylinder H3.

The operating linkage for contact it com-- prises two levers I14 andI15. The former is pivoted at I76 and the latter at I'Ii. Tie link I78interconnects levers iii and I75. Operating rod H9 interconnects pistonrod I35 of motor I25 and lever I75. Lever I75 is provided with a rollerI89 adapted to be engaged by the main latch I35 under the action ofbiasing spring lei). Main latch I39 is pivoted at It! and controlled bythe spring biased auxiliary latch I42. Auxiliary latch I 52 is in turncontrolled by tripping solenoid M3.

The piston rod I8! of fluid motor I'i't is connected to lever I74 by alink I82. A roller I'Id on the pin interconnecting link I82 and lever INis guided by cam surface I83 and held in position by spring biased latchI54. Latch I84 is in turn controlled by a latch 555 adapted to beoperated by a tripping solenoid I55. Pipeline I88 connects one tap ofthe fluid motor piston valve unit I9, I56 with fluid motor Ilil. Thispipeline is under the control of solenoid operated valve I81. PipelineI59 connects another tap of the fluid motor piston valve unit I9, 559with fluid motor l25. This pipeline is under the con trol of latchchecking valve I59 which insures that the main closing motor I25 cannotbe supplied with fluid under pressure unless the latch mechanism I84,I85 is in locked position.

The energizing circuit of solenoid operated valve I81 includes aninterlock switch I99 adapted to be operated by piston rod ltl of fluidmotor I by means of an operating rod I9I. Switch I99 is spring biased toopen position in which it prevents the solenoid oi solenoid operatedvalve I81 from being energized. When the piston I12 of fluid motor I18moves to its upper position, piston rod I8I acts upon operating rod lillto close interlock switch I99.

The circuit breaker illustrated open in Fig. 5 is manually closed bymeans of pushbutton I52. This results in operation of valve I45 topermit fluid under pressure from tank it to actuate piston I55 of motorI9 and valve i5!) from left to right. After piston i55 has completed.part of its stroke air flows from the cylinder of mo tor I9 throughvalve I59 and pipeline I59 to inotor I25. Piston I21 is actuated upwardagainst the bias or spring I26 to close the disconnect contacts I5 andI6 through the levers I14, E and I18 and is latched in place by latchesI39 and I42. Dump valve E29 remains closed during most of the closingstroke of the breaker as a result of the lost motion connectionassociated with rod I53 and the dump valve actuating rod. At the end ofthe stroke of piston I55 from left to right, switch I54 interrupts theenergizing circuit of valve I48.

Manual opening of the circuit breaker illustrated in Fig. 5 may beefieoted by actuating pushbutton I6I, causing energization of trippingvalve I51 and the same sequence of operation as described above for theembodiment illustrated in Fig. 1. During manual opening, switch I56 ismoved to its lower position to preclude automatic reclosing of thebreaker.

If reclosing cutout switch I55 is in the upper position an automaticreclosing sequence of operation of the circuit breaker system willoccur. The circuit breaker being closed, energization of relay I51starts reclosing relay I58, which looks itself in circuit. Energizationof relay I51 also results in closing of the circuit of solenoid valveI41 through switch I54 and consequently in admission of compressed airto the right side of fluid motor I9 and piston valve I59. Piston I55 ofmotor I9 and the movable valve element oi valve I50 are thereby movedfrom right to left. This movement of piston 55 causes a rotation ofcolumn I8 which in turn causes momentary opening of blast valve 3i andseparation or con tacts and 2|. The movement of piston I55 to the leftoperates auxiliary switch I54.

When piston I55 of motor I9 reaches its left position, switch I54energizes the circuit of solenoid I86 through reclosing relay I53.Solenoid I86 unlatches latch 154 and spring I'll or motor I10 expands,thereby causing lever I14 to rotate counterclockwise about the pointwhere it is hingedly connected to link I18. Roller I16 moves up alongthe cam surface I83 as disconnect oontact I6 is moved a reduced stroketo the position shown in dotted lines in Fig. 5. The position of thelatch members I84, I85, I42 and I39 for the reduced stroke of thedisconnect contact I6 is illustrated in Fig. 8. At that time piston rodI8I closes valve I89 and switch I90. Relay I51 returns to the positionshown.

Switch I54 in its movement from right to left also deenergizes solenoidI86 so that latch I may reset. However, while piston I12 moves downwardroller I16 moves along an extension of latch I84 so that latches I84 andI85 are prevented from returning to the latching portion of Figs. 5 and'1 until piston I12 has completed its downward stroke.

When piston I55 of motor I9 is in its left position, switch I54 causesopening of the solenoid valve I41 and closing of the circuit of thesolenoid valve I48 through relay I58. Consequently, the flow ofcompressed air through pipe I49 is interrupted and a flow of compressedair is established through pipe I5I. The latter flow causes a motion ofthe piston I55 and of the movable element of valve I58 from left toright. This movement of piston I55 results in arotation of insulatingcolumn I8 which, in turn, recloses contacts 25 and 2 I.

Movement of the valve element of piston valve I59 to the right causesadmission of air under pressure from the cylinder of fluid motor I9 tothe pipes I59 and I88. Compressed air admitted to pipe I59 remainsineffective since that pipe is blocked by latch checking valve I89 movedto closed position through the previous operation of spring I1! and rodI8I.

As piston I55 of motor I9 moves from left to right auxiliary switch IE4is moved from right to left and closes the circuit which energizessolenoid valve I51 through switches lei! and I56 and relay I58. ValveI81 is thereby opened and compressed air is then admitted to thecylinder I13 of fluid motor I15, causing the downward movement of pistonI12 against the action of spring ill, thus reclosing contacts I5 and I5.Reclosing of contacts I5 and I5 results in reclosing of the controlledpower circuit.

What happens further depends on whether or not the fault still prevailsat the time disconnect contacts I5 and I5 reengage. If the fault doesnot prevail at that time the continuity of the system is maintained. Ifthe fault still persists, the circuit breaker proceeds to effect apermanent interruption of the power circuit.

Upon reclosure of contacts I5, I5, permanent interruption is initiatedby reenergizing relays I51 and I41, resulting in admission or compressedair to motor I9. Piston I55 of motor I9 then moves from right to left,resulting in momentary opening blast valve 3| and in separation ofarcing contacts 20, 2%. The power circuit is again interrupted.

During the initial interrupting sequence, motor controlled relay I58moved so that at this time the control circuit passing therethrough andthrough switch I54 will energize solenoid I43 but not solenoid I86.

Solenoid I43 causes auxiliary latch I42 to move counterclockwise andrelease main latch I39. Roll I89, as shown, in Fig. 7 is deprived of itssupport and spring I26 is free to move linkage I14, I15, I18 from itsposition shown in Fig. 7 to its position shown in Figs. 5 and 6. Thiscompletes the opening operation of the circuit breaker and results inseparating the disconnect 13 contacts their full strok as distinguishedfrom part stroke separation.

Although but two embodiments of the Dresent invention have beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims. In particular, while the specific structures shown inthe drawing are high voltage air blast circuit breakers of th axialtype, the invention is also applicable to circuit breakers of othertypes such as for instance oil poor or small volume oil circuitbreakers.

Features disclosed but not claimed herein are claimed in U. S. PatentNo. 2,568,008, granted upon the application of Gustav E. Jansson.

t is claimed and desired to secure by Letters Patent:

1. In combination, an electric circuit, a circuit breaker comprisingserially connected cooperating arcing contact means and. disconnect,

contact means, said disconnect contact means arranged to insert circuitinsulation into said circuit selectively at relatively small gap lengthand at relatively large gap length, means respontive to an overloadcondition of said circuit for causing separation of said arcing contactsand interruption of said circuit at the gap formed between said arcingcontacts, means operative upon initial interruption of said circuit atsaid arcing contacts for causing said disconnect contact means to openand to insert circuit insulation at said small gap length into saidcircuit, means operative upon said insertion of circuit insulation atsaid small gap length for causing said arcing contacts and saiddisconnect contact means to be reclosed sequentially, and meansoperative only upon repeated interruption of said circuit at said arcingcontacts for causing said disconnect contact means to insert circuitinsulation at said large gap length into said circuit.

2. In combination, an electric circuit, a circuit breaker comprisingserially connected arcing contacts and disconnect contacts connected insaid circuit, an arcing contact operator for providing relative shortstroke movements between said arcing contacts, a disconnect contactoperator for providing selectively relative short stroke and. longstroke movements between said disconnect contacts, means responsive toan overload condition of said circuit for actuating said arcing contactoperator to separate said arcing contacts, means for actuating saiddisconnect contact operator to separate said disconnect contacts atsmall gap length upon initial opening of said arcing contacts, means foractuating said arcing contact operator to reclose said arcing contactsupon separation of said disconnect contacts at small gap length, meansfor actuating said disconnect contact operator to reclose saiddisconnect contacts upon separation thereof at small gap length, andmeans operative only upon repeated interruption of said circuit at saidarcing contacts for actuating said disconnect contact operator toseparate said disconnect contacts at large gap length.

3. An electric circuit breaker comprising in combination, a source ofgas under pressure, a pair of relatively movable cooperating arcingcontacts, means for actuating said arcing contacts, means forestablishing and maintaining a blast of gas from said source adjacentsaid arcing contact when separated by said actuating means, a pair ofrelatively movable disconnect contactsconnectedin series with saidarcing contacts, a first disconnect contact operator provided to eiiectsmall relative movements between said disconnect contacts, a seconddisconnect contact operator provided to effect large relative movementsbetween said disconnect contacts, tripping means for actuating saidarcing contact operator to separate said arcing contacts, means foractuating said first disconnect contact operator to separate saiddisconnect contacts upon initial separation of said arcing contacts,means for actuating said arcing contact operator to close said arcingcontacts upon separation of said disconnect contacts, means for causingsaid first disconnect contact operator to close said disconnect contactsupon reengagement of said arcing contacts, and means operative only uponrepeated opening of said arcing contacts for actuating said seconddisconnect contact operator to separate said disconnect contacts.

i. In combination, an electric circuit, a circuit breaker comprising apair of cooperating arcing contacts, contact means in series with saidarcing contacts for selective insertion into said circuit a relativelysmall amount of circuit insulation at a gap of relatively small lengthformed in a medium of relatively high dielectric strength and of arelatively large amount or circuit insulation at a gap of increasedlength formed in air at atmospheric pressure, means responsive to anoverload condition of said circuit for separating said arcing contactsto interrupt said circuit, means operative upon initial interruption ofsaid circuit at said arcing contacts for causing said contact means toinsert circuit insulation at small gap length into said circuit, meansoperative upon insertion of circuit insulation at small gap length forreengaging said arcing contacts, means for reclosing said additionalcontact means upon reclosing of said areing contacts, and meansoperative only upon repeated interruption of said circuit at said arcingcontacts for causing said additional contact means to insert circuitinsulation at large gap length into said circuit.

5. In combination, an electric circuit, a circuit breaker comprising apair of circuit interrupting contacts, a pair of circuit closingcontacts, and a pair of disconnect contacts, all said contacts beingserially connected in said circuit, an interrupting contact operator foreiTecting relative short stroke movements between said interruptingcontacts, a closing contact operator for efrecting relative short strokmovements between said closing contacts, fault responsive tripping meansfor causing said interrupting contact operator to open said interruptingcontacts en the occurrence of a fault in said circuit, means for causingsaid closing contact operator to open said closing contacts upon initialopening of said interrupting contacts, means for causing saidinterrupting contact operator to reclose said interrupting contact uponopening of said closing contacts, means for causing said closing contactoperator to reclose said closing contacts upon reclosing of saidinterrupting contacts, a disconnect contact operator for effectingrelative long stroke movements between said disconnect contacts, andmeans operative onl upon repeated opening of said interrupting contactsfor causing said disconnect contact operator to open said disconnectcontacts.

6. In combination, an electric circuit, a circuit breaker comprising apair of cooperating interrupting contacts of the nozzle and plug type,

a pair of closing contacts of the engageable finger type, and a pair ofdisconnect contactsof the engageable finger type, all said contactsbeing serially connected into said circuit, an interrupting contactoperator for effecting relative short stroke movements between saidinterrupting contacts, a closing contact operator for effecting relativeshort stroke movements between saidclosing contacts, fault responsivetripping means for causing said interrupting contact operator to opensaid interrupting contacts to draw an arc therebetwecn, means forproducing an are extinguishing blast of fluid across the gap formed uponopening of said interrupting contacts, means for causing said closingcontact operator to open said closing contacts upon opening of saidinterrupting contacts extinction of said are, means for causing saidinterrupting contact operator to reclosc said interrupting contacts uponopening of said closing contacts, means for causing said closingcontact, operator to reelose said closing contacts upon reclosing ofsaid interrupting contacts, a disconnect contact operator for effectingrelative long stroke movements between said disconnect contacts, andmeans operative only upon repeated opening of said interrupting contactsfor causing said disconnect contact operator to open said disconnectcontacts.

7. In combination, an electric circuit, a circuit breaker comprising apair of circuit interrupting contacts, a separate pair of circuitclosing contaste, and a separate pair of disconnect contacts, saidinterrupting contacts, closing contacts and disconnect contacts beingserially connected into said circuit, an operator for effecting relativemovement between said interrupting contacts, an operator for effectingrelative movement between said closing contacts, means responsive to anoverload condition of said circuit for opening said interruptingcontacts, means operative upon opening of said interrupting contacts foropening said closing contacts, means operative upon opening of saidclosing contact for closing of said interrupting contacts, meansoperative upon closing of said interrupting contacts for rcengaging saidclosing contacts, a source of gas under pressure, means for admitting ablast of gas from said source adjacent said interrupting contacts duringseparation thereof, means for admitting gas under pressure from saidsource adjacent said closing contacts during the sepa ration thereof, anoperator for effecting relative movement between said disconnectcontacts, and means operative only upon repeated opening of saidinterrupting contact for separating said disconnect contacts.

3. An electric circuit breaker comprising in combination, a source ofgas under pressure, an insulating blast passage connected at one endthereof with said source, a main valve arranged adjacent the oppositeend of said passage for con trolling a blast of gas issuing therefrom, apair of relatively movable circuit interrupting contacts arrangedadjacent the region of saidblast, an interrupting contact operatorarranged at ground potential, a rotatable insulating column adapted atone end thereof to be rotated by said interrupting contact operator, andat the opposite end thereof arranged to operate one of said interruptingcontacts and to initiate the operation of said main valve, a contactchamber, an auxiliary valve under the control of said insulating columnfor admitting gas under pressure from said passage to said chamber, apair of relatively movable circuit closing contacts arranged in saidchamber" and arranged to" be" 16 connected in series with saidinterrupting contacts, closing contact operating means arranged at anelevated potential and under the control of said column for effectingrelative movement between said closing contacts, tripping meansresponsive to a circuit condition for actuating said interruptingcontact operator to separate said interrupting contacts, means foractuating said closing contact operating means to open said closingcontacts upon opening of said interrupting contacts, means for actuatingsaid interrupting contact operator to close said interrupting contactsupon opening of said closing contacts, means for actuating said closingcontact operating means to reengage said closing con tacts upon closingof said interruptingcontacts, a separate pair of relatively movabledisconnect contacts connected in series with said interrupting contactsand said closing contacts, a disconnect contact operator for effectingrelative movement between said disconnect contacts, and means forcausing said disconnect contact operator to separate said disconnectcontacts upon repeated opening of said interrupting contacts.

9. An electric circuit breaker comprising in combination, a source ofgas under pressure, means defining a first contact chamber, a pair orrelatively movable circuit interrupting contacts in said first contactchamber, means defining a. second contact chamber arranged generallytransverse with respect to said first contact chamber, a pair ofrelatively movable circuit closing contacts in said second contactchamber arranged to be connected in series with said interruptingcontacts, an operator for efiecting relative movement between saidinterrupting contacts, an operator for effecting relative movementbetween said closing contacts, fault responsive means for opening saidinterrupting contacts, means operative upon opening of saic interruptingcontacts for opening said closing contacts, means operative upon openingof said closing contacts for closing of said interrupting contacts,means operative upon closing of said interruptingv contacts forreengaging said closing contacts, common means for admitting gas underpressure from said source to said first contact chamber and said secondcontact chamber, a pair of relatively movable disconnect contactsconnected in series with said interrupting contacts and said closingcontacts, an operator for effecting relative movement between saiddisconnect contacts, and means operative only upon repeated opening ofsaid interrupting contacts for causing opening of said'disconnectcontacts.

10'. An electric circuit breaker comprising in combination, a source ofgas under pressure, a pair of relatively movable circuit interruptingcontact comprising a nozzle shaped contact and a cooperating plug shapedcontact, a pair of relatively movable circuit closing contactscomprising a plurality of finger type contact elementsarranged to engagea cooperating contact element on opposite surfaces thereof, a firstoperator for actuating said pair of interrupting contacts, a secondoperator for actuating said pair of closing contacts, fault responsivemeans for causing admission of gas under pressure from said sourceadjacent said pair of interrupting contacts and adjacent said pair ofclosing contacts and for opening said pair of interrupting contacts,means for actuating said second operator to open said pair of closingcontacts upon opening of said pair of interruptingcontacts andextinctionot the are formed therebetweem-meaxw for actuating said firstoperator to reclose said pair of interrupting contacts upon opening ofsaid pair of closing contacts, means for actuating said second operatorto reclose said pair of c1osing contacts upon reclosing of said pair ofinterrupting contacts, a pair of relatively movable disconnect contacts,means for serially connecting said pair of interrupting contacts, saidpair of closing contacts and said pair of disconnect contacts into acircuit, a. third operator for effecting relative movement between saidpair of disconnect contacts, and means operative only upon 18 repeatedopening of said pair 01' interrupting contacts for causing said thirdoperator to open said pair of disconnect contacts.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,430,128 Lerstrup Nov. 4, 1947 2,464,237 Kelle Mar. 15, 19492,528,694 Kelle Nov. 7, 1950 2,533,559 Chipman Dec. 12, 1950

